Isolation of amniotic fluid erythrocytes and their possible use in prenatal diagnosis.

Many of the components of amniotic fluid have been found to be valuable in prenatal diagnosis; however, the presence of erythrocytes is usually considered undesirable. The authors have used buoyant density centrifugation on 96 amniotic fluid specimens from 70 subjects to isolate small numbers of erythrocytes from a majority of these specimens. Through immunofluorescence, these specimens were found to have higher levels of fetal hemoglobin-containing cells than the adult, indicating that the erythrocytes were at least in part fetal in origin. Thus, erythrocytes present in amniotic fluid could also be used in prenatal diagnosis.